There are many nutritional dietary supplements known in the art that are commercially available. Most consist of a protein component, a carbohydrate component, a lipid fraction and any number of other components such as vitamins, stabilizers, emulsifiers, flavor agents and the like. These are particularly of value in the treatment of patients who are too old, sick or disabled to bite, chew and swallow their food. The liquid nutritional formulations can be administered to the patient by using a gastrostomy or enteral feeding tube. Gastrostomy tubes enter the stomach directly through an incision in the stomach known as an ostomy or down the through the mouth and throat.
The use of enteral feeding tubes which supply nutritional requirements of a patient directly to the stomach or other location in the digestive tract is often required when the patient for one reason or another cannot swallow, is unable to chew his or her food, or is unable to ingest enough food to meet the body's caloric requirements. Burn victims, the chronically ill, those afflicted with Alzheimer's disease and cancer patients are prime examples of these types of individuals. Enteral feeding usually employs a nasogastric tube to transport the liquid nutritional products through the nasal cavity and pharayrx and into the stomach.
U.S. Pat. No. 5,576,287 to Zalaga et al. refers to a nutritional composition allegedly useful in the treatment of renal failure comprising a liquid formulation consisting of meat proteins or meat and vegetable proteins with a mixture of amino acids, peptides and polypeptides. Soy protein is not specifically taught and none of the meat or vegetable proteins are specifically disclosed. At least 15% of the formulation is protein.
U.S. Pat. No. 5,821,217 to Forse et al. refers to an enteral nutritional formulation consisting of a fat component (2.0-4.0 gm/l), a protein hydrosylate component (50-100 gm/l), a carbohydrate component (160-250 gm/l) and water. Soy protein hydrosylate is one of a number of possible protein components such as casein, whey, lactalbumin and the like. Safflower oil and sunflower oil comprise the preferred fats, and corn starch is the preferred carbohydrate. The formulations are disclosed as being particularly useful in the treatment of critically ill patients while minimizing the risk of pulmonary aspiration and/or gastrointestinal dysfunction.
U.S. Pat. No. 5,308,832 to Garleb et al. refers to a low carbohydrate, high fat nutritional formula useful in treating patients with neurological injury and/or disorders. The composition consists of a lipid blend of fatty acids (70%-80% of the total caloric content) a protein component (15%-30% total caloric intake) and a carbohydrate fraction (.ltoreq.5.0% caloric content). The formulation may further comprise dietary fiber and/or an antioxidant (e.g., vitamins).
U.S. Pat. No. 5,229,136 to Mark et al. refers to a low caloric density enteral feeding composition comprising a protein component (which provides 18-25% of the total caloric content of the composition), a fat component (35%-50% of the total caloric content of the composition), a fiber component (.ltoreq.14 grams/liter) and a carbohydrate component (35%-40% caloric content). Protein sources may include casein, hydrolyzed whey protein and hydrolyzed soy protein. Suitable lipids include medium chain triglycerides blended with soy oil and maltodextrin may be used as the carbohydrate. The formulation is disclosed as being particularly useful in the treatment and prevention of diarrhea.
U.S. Pat. No. 4,670,268 to Mahmond discloses and claims an enteral nutritional hypoallergenic formula consisting of a carbohydrate component (8.0%-20% caloric content) and an emulsifier consisting of dextrinized starch modified by octeryl succinic acid anhydride which causes the formulation to form a stable, non-browing emulsion. The composition may also further comprise free amino acids and carrageenan or xanthan gum as additional stabilizers. Soy bean, whey or casein hydrosylates may comprise the protein fraction while sucrose, maltodextrin, hydrolyzed starch and a laundry list of other starches and sugars may comprise the carbohydrate fraction. Safflower oil, soy oil and medium chain triglycerides serve as the lipid component. Whereas the formulation per se is admittedly not highly novel, the use of the emulsifier as the stabilizing component is the heart of the invention.
A number of other United States patents disclose methods and processes for preparing defatted soy, stabilized soy protein base and phosphorylated soy protein for use in food and beverage applications. See e.g., U.S. Pat. No. 4,322,344 to Chen et al; U.S. Pat. No. 3,846,560 to Hempenis et al; U.S. Pat. No. 3,713,843 to Pam-el et al. and U.S. Pat. No. 3,645,745 to Magnino et al.
European Patent Application No. EP 0 626 175 A2 to Dewille et al. discloses a liquid enteral nutritional product consisting of soy protein hydrosylate fraction (50-90 wt %), an intact protein fraction (10 wt %-30 wt %) consisting of sodium caseinate, pea or whey protein, and carrageenan.
European Patent Application EP 0 626,176 A2 to Cope et al. discloses and claims a nutritional formulation for patients undergoing chemotherapy consisting of a soy protein hydrosylate component (up to 90 wt %), intact protein (10 wt %) such as pea and whey protein and fat. The composition may further comprise dietary fiber and .beta.-carotene.
European Patent Application EP 0 603,726 A2 to Dube et al. discloses nutritional compositions for enteral feeding containing a vitamin D ester, an amino acid source, a carbohydrate component and a lipid component. The compositions are asserted to have improved vitamin D storage stability. Soy protein is one of a number of enumerated amino acid sources that also include casein, whey protein and protein hydrosylate. Corn syrup is also one of many enumerated carbohydrates useful in the preparation of the composition.
European Patent Application No. EP 0 564,804 A1 to Trimbo et al. discloses an improved high protein liquid nutrition formula particularly useful in the treatment of patients with elevated wound healing requirements. The composition consists of a protein component, a fat source, a carbohydrate component, a source of zinc, vitamin A, .beta.-carotene and a source of thiamine. Dietary fiber may also optionally be added in the form of soy polysaccharide. Soy protein is again listed as a possible protein component and preferably comprises at least 18% of the total composition.
International Application No. PCT/US96/19665 to Antinone et al. discloses a method for the preparation of a stable liquid nutritional composition consisting of a protein source, carbohydrates, oils and soy polysaccharide as a source of dietary fiber. Soy protein is listed as one of a number of possible protein sources.
European Patent Application Nos. EP 0 666,034 A1 and EP 0 752,212 A2 both to Samoto et al. disclose a process for the preparation of fractionated soy bean proteins and nutritional compositions comprising them. The defatted fractional protein compositions are associated with soybean.
It is an object of the present invention to prepare a stable, highly nutritional liquid formulation in which substantially all of the protein incorporated therein comes from soy. It is a further object of the present invention to prepare a highly nutritional liquid composition wherein the protein source is comprised of soy protein isolate or a combination of soy protein isolate and soy protein concentrate. A unique combination of the soy together with a number of other components allows for the preparation of a highly nutritional shelf stable soy protein formulation that is both temperature and shelf stable with none of drawbacks or limitations often associated with soy-based products.